College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, Zhejiang, China.
Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, PO Box 27, Helsinki, FI-00014, Finland.
New Phytol. 2020 Jan;225(2):782-792. doi: 10.1111/nph.16170. Epub 2019 Oct 13.
Soil phosphorus (P) availability and its distribution influence plant growth and productivity, but how they affect the growth dynamics and sex-specific P acquisition strategies of dioecious plant species is poorly understood. In this study, the impact of soil P availability and its distribution on dioecious Populus cathayana was characterized. P. cathayana males and females were grown under three levels of P supply, and with homogeneous or heterogeneous P distribution. Females had a greater total root length, specific root length (SRL), biomass and foliar P concentration under high P supply. Under P deficiency, males had a smaller root system than females but a greater exudation of soil acid phosphatase, and a higher colonization rate and arbuscular mycorrhizal hyphal biomass, suggesting a better capacity to mine P and a stronger association with arbuscular mycorrhizal fungi to forage P. Heterogeneous P distribution enhanced growth and root length density (RLD) in females. Female root proliferation in P-rich patches was related to increased foliar P assimilation. Localized P application for increasing P availability did not enhance the biomass accumulation and the morphological plasticity of roots in males, but it raised hyphal biomass. The findings herein indicate that sex-specific strategies in P acquisition relate to root morphology, root exudation and mycorrhizal symbioses, and they may contribute to sex-specific resource utilization patterns and niche segregation.
土壤磷（P）的有效性及其分布会影响植物的生长和生产力，但人们对其如何影响雌雄异株植物物种的生长动态和性别特异性 P 获取策略知之甚少。本研究旨在探讨土壤 P 有效性及其分布对雌雄异株的枫杨的影响。在三种 P 供应水平下，对枫杨的雄性和雌性个体进行培养，并采用同质或异质 P 分布方式。在高 P 供应下，雌性个体的总根长、比根长（SRL）、生物量和叶片 P 浓度均较大。在 P 缺乏条件下，雄性个体的根系小于雌性个体，但分泌的土壤酸性磷酸酶较多，丛枝菌根真菌的定殖率和菌根菌丝生物量较高，表明其具有更强的 P 挖掘能力和与丛枝菌根真菌更强的联系以获取 P。异质 P 分布可增强雌性个体的生长和根长密度（RLD）。富含 P 的斑块中雌性根的增殖与叶片 P 同化的增加有关。局部施用 P 以增加 P 的有效性并没有增强雄性个体的生物量积累和根系的形态可塑性，但提高了菌丝生物量。研究结果表明，P 获取的性别特异性策略与根系形态、根系分泌和菌根共生有关，它们可能有助于性别特异性资源利用模式和生态位分离。
